ARCHIVED REPORTS_XR0009745 - Laserfiche WebLink

Home Browse Search

J. In August 1993, wells MW-1, MW-2, and MW-3 were monitored and sampled Analytical results showed that M`W-1 had no measurable concentrations of petroleum hydrocarbons in the groundwater Wells MW-2 and MW-3 contained detectable levels of petroleum hydrocarbons A program of quarterly groundwater monitoring and sampling was begun in March 1994 In August 1995, Smith Environmental conducted a subsurface site investigation to further define the extent of contamination in groundwater at the site Smith Environmental supervised the installation of monitoring wells MW-4, IMW-5 and MW-6 These three new wells were developed and sampled along with monitoring wells MW-1, MW-2, and MW-3 Analytical results of groundwater samples from the sic morutonng wells indicated the presence of elevated concentrations of petroleum hydrocarbons in the vicinity of wells MW-3 and MW-6, on the northeast corner of the site n PROPOSED SCOPE OF WORK Smith Environmental proposes the following scope of work to evaluate potential groundwater contamination at the subject site Installation of Two Groundwater Wells and Three Vapor Wells This task includes mobilization to the site, advancing two soil borings off-site and completing them as groundwater monitoring wells, and then advancing three soil borings on-site and completing them as vapor wells The proposed locations of the groundwater and vapor wells are shown on Figure 2 The two off-site borings will be advanced to depths of 40 feet below ound surface gs and gr (bgs), the three on-site borings will be advanced to depths of 30 feet bgs using 8-inch O D hollow stem augers Drilling will be conducted by Spectrum Exploration, Inc , a State-licensed (C57) drilling company A field geologist will be present to log all drill cuttings and soil samples Descriptions of soil types encountered, sample collection intervals, and well construction details will be recorded on boringlwell logs Soil samples will be collected at five foot intervals and up to two samples from each boring will be submitted for laboratory analysis of total petroleum hydrocarbons as gasoline (TPHg) and benzene, toluene, ethylbenzene, and xylenes (BTEX) Selected soil samples will be sent using chain-of-custody record to a State-certified laboratory for analysis of TPHg and BTEX. The two off-site bonngs will be completed as groundwater monitoring wells with screened intervals from approximately 25 to 40 feet bgs, and the three on- site borings will be completed as vapor wells with screened intervals from approximately 10 to 30 feet bgs The wells will be constructed of 2-inch inside diameter PVC well screen and casing To protect the integrity of the wells, locking, water-tight well plugs will be installed on each well, and water-tight, traffic rated, wellheads labeled "monitoring well" wiII be concreted over each well All drill cuttings will be drummed and stored on-site pending laboratory results . 111'94373%rcpwukwp0496&= 2 • SMl"H